Tudors and Stuarts
In the time of the Tudors, it became common practice for the Crown to grant monopolies for trades and manufacturers, including patents for invention. From 1561 to 1590, Elizabeth I granted about 50 patents whereby the recipients were enabled to exercise monopolies in the manufacture and sale of commodities such as soap, saltpetre, alum, leather, salt, glass, knives, sailcloth, sulphur, starch, iron and paper.
Under Elizabeth I and her successor James I, the granting of monopolies for particular commodities became increasingly subject to abuse. It was common for grants to be made for inventions and trades that were not new. In some instances, grants were made to royal favourites for the purpose of replenishing royal coffers.
In 1610, James I was forced by mounting judicial criticism and public outcry to revoke all previous patents and declare in his "Book of Bounty" that 'monopolies are things contrary to our laws' and "we expressly command that no suitor presume to move us". He stated an exception to this ban for "projects of new invention so they be not contrary to the law, nor mischievous to the State".
The doctrine of the public interest was introduced into the patent system and the words were incorporated into the Statute of Monopolies of 1624. Section 6 of the Statute rendered illegal all monopolies except those "for the term of 14 years or under hereafter to be made of the sole working or making of any manner of new manufactures within this Realm to the true and first inventor".